From 1976 to 1981, 335 patients with untreated Hodgkin's disease, clinical stages I, II, and IIIA, have been treated by MOPP (nitrogen mustard, vincristine, procarbazine, prednisone) chemotherapy, three to six cycles according to the prognostic factors, combined with radiotherapy. Irradiation was always performed after the first three cycles of chemotherapy, and was randomized between extensive radiotherapy, ie, mantle and paraaortic areas for supradiaphragmatic presentations, and radiotherapy restricted to the involved areas. No significant difference was observed between the two randomized branches for the disease-free survival (86% after six years in the involved field branch v 90% in the extended field branch), and none for the overall survival. Most of the relapses occurred in nonirradiated areas in the first group, and in irradiated areas in the second. Relapses were especially frequent in the IIE stages with pulmonary extension; extranodal relapses occurred with osseous and cutaneous localizations. Two cases of secondary leukemia were observed after three- or six-cycle MOPP plus radiotherapy limited to the involved areas.